1. Field of the Invention
The present invention concerns a combined fastening device for transporting a turbojet engine and hoisting it into an airframe. The fastening device has fixation elements for fixation to the transport truck and means for hoisting of the unit into position in the airframe.
2. Description of the Prior Art
The main housing of a turbojet engine conventionally carries a number of elements located in symmetric pairs in relation to the vertical plane of symmetry of the housing and intended for the fixation of the unit to a transport truck used for placing and removing the unit into and from the airframe as well as for its longitudinal positioning. Also provided are elements for the fixation of hoisting means allowing lifting or setting up of units onto the transport truck and its placing in a vertical direction for fixing to the airframe, and for the fixation of units to the airframe, e.g. by means of small rods.
Due to the specificity of each pair of elements, they are distributed over a large angular sector of the housing, which requires a reinforcement of this entire area. The consequences are a poor distribution of stress and an increase in the mass of the turbojet engine.
Attempts have been made to simplify and lighten the fixing and hoisting systems. Thus, French Pat. No. 2,326,327 describes a device which permits the vertical movement of a turbojet engine using a single element. This element is compounded with a peg fixed to the top of the engine housing. The peg has the function of centering the unit in relation to a bearing fixed to the upper part of the airframe. The peg is provided along its longitudinal axis with structure for fixing a hoisting device passing through the journal bearing and allowing the vertical placement or the removal of the engine by a winch. The unit is conventionally fixed to the airframe by lateral rods.
This device allows the elimination of a hoisting point and of a hoisting system independent of the assembly, but has the disadvantage of subjecting a small area of the housing to significant stresses.
French Pat. No. 2,453,779 discloses a device in which the fixing small rods and the hoisting element are merged together. The housing of the turbojet engine carries two small rods which are symmetric to its vertical plane of symmetry and are articulated to straps integral with the housing. The other end of each of the small rods cooperates with a connecting and raising assembly. This assembly has a nut and screw linear moving system on the small rod side and is suspended from the airframe by a spherical articulation.
Aside from the reduction in the number of elements necessary for fixing and raising, this device does not take up much space and allows a reduction of dead spaces in comparison with conventional fixation devices.